Tag Archives: highway signs

Existing 80 mph zone on northbound I-15 near Paragonah. Photo taken by Ming Jiang of the Traffic and Safety Division.

A number of bills passed by the legislature this past session affect Utah roads and highways. One of these bills was HB 83: Speed Limit Amendments. This bill expands portions of I-15, I-80, and I-84 where the Utah Department of Transportation may establish a posted speed limit that exceeds 75 miles per hour. These sections of freeway include, portions of I-15 from Santaquin to St. George and from Brigham City to the Utah-Idaho border. Portions of I-80 potentially affected will be from Grantsville to the Utah-Nevada border and I-84 from Tremonton to the Utah-Idaho border.

If the Department of Transportation chooses to increase the speed limit in these sections the department will evaluate the results and impacts of increasing the speed limit and will report the findings of the evaluation to the Transportation Interim Committee no later than one year after the speed limit is posted.

This bill continues a process which began a number of years ago to evaluate some of Utah’s interstates to determine if there are areas that could appropriately accommodate speed limits above what is currently posted.

Opponents of this bill feared that with an 80 mile per hour speed limit there would be an increase in accidents and that drivers would increase their speed beyond 90 miles an hour. Through the studies conducted over the past few years the department has found that this is not the case.

Beginning in 2008, studies were conducted on portions of I-15, where the speed limit was increased from 75 to 80 mph. The studies concluded that most drivers preferred to drive between 82 and 83 mph regardless of the posted speed limit. Accident rates on these stretches of freeway were also studied and concluded that the increased speed did not affect the number of accidents or fatalities.